Using dimensional weight for calculated shipping rates

Many carriers calculate shipping rates based on the dimensional or volumetric weight of your shipments. The dimensional weight is calculated according to a formula that uses your default shipment dimensions. Dimensional weight accounts for the amount of space that a package takes up while it's being shipped to its destination.

If you use one default box size to ship your orders, then your Default shipment dimensions generates correct calculated shipping rates. If you ship packages in more than one box size, then you should use an app for greater accuracy.

How dimensional weights work

Your default package dimensions are sent to your shipping carrier along with your order's weight to calculate shipping rates for your customer. Dimensional weight is determined by the carrier based on the height, width, and depth of your packages. Dimensional weight applies to some shipping services when a package's total length x width x height exceeds 1 cubic foot (1728 cubic inches).

If your dimensional weight is larger than your order's weight, then your customer is charged for the dimensional weight of their order. If you think that the generated rates are too high or too low, then you can adjust your calculated rates to increase or decrease your shipping rates as needed.

Dimensional weight calculations vary between carriers. Consult the carrier you're using for details about their dimensional weight policies.

Carriers with dimensional weight policies:

Carriers without dimensional weight policies:

Configure your default package dimensions


  1. In the Packages section, click the title of the package that's beside the Default label:

  2. Enter a title, the dimensions, and weight of your default shipment package:

  3. Click Save.

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